Various wireless communication technologies systems have been developed with rapid development of information communication technologies. WLAN technology from among wireless communication technologies allows wireless Internet access at home or in enterprises or at a specific service provision region using mobile terminals, such as a Personal Digital Assistant (PDA), a laptop computer, a Portable Multimedia Player (PMP), etc. on the basis of Radio Frequency (RF) technology.
In order to obviate limited communication speed, one of the advantages of WLAN, the recent technical standard has proposed an evolved system capable of increasing the speed and reliability of a network while simultaneously extending a coverage region of a wireless network. For example, IEEE 802.11n enables a data processing speed to support a maximum high throughput (HT) of 540 Mbps. In addition, Multiple Input and Multiple Output (MIMO) technology has recently been applied to both a transmitter and a receiver so as to minimize transmission errors as well as to optimize a data transfer rate.
Machine to Machine (M2M) communication technology has been discussed as next generation communication technology. A technical standard for supporting M2M communication in IEEE 802.11 WLAN has been developed as IEEE 802.11ah. M2M communication may sometimes consider a scenario capable of communicating a small amount of data at low speed in an environment including a large number of devices.